A disposable syringe for liquid injection on which the present invention can be said to be based is described in detail in the U.S. Pat. No. 5,032,114, which illustrates a syringe of the kind described in the introduction and with which the means which functions to connect and disconnect the piston to and from the rod has a screw thread configuration. The embodiments of the rod disconnecting and connecting means described in this international patent application in FIGS. 6 and 9 can be said to constitute the closest relevant prior art.
Other disposable injection syringes are also known to the art, for instance the syringe described and illustrated in Swedish Patent Publication SE-B-79 02138-2, publication No. 438 598.
The injection syringe described and illustrated in the European Patent Publication EPA2-0 229 017 also forms part of the prior art.
Also forming part of the known art is the rod configuration described in publication U.S. Pat. No. 5,004,460 and illustrated in FIG. 7 of said publication.
In addition to the aforecited publications, reference is also made to the piston and rod coupling means illustrated and described in patent publications U.S. Pat. No. 4,906,231, FR-A-2 381 527 and NO-A-163 263.